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Odd noise after engine work (EA81)


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If you have been following along ive put together a slightly hi compression EA81 with solid lifters. Specs on the heads are

 

.030 shaved off each head

ported and polished

5 angle valve job.

 

I got it up and running tonight for the first time. It idles super smooth and quiet. In fact its quieter than the hydro lifter EA81 that it replaced. That is until i step on the gas.

 

When i step on the gas and let out the clutch to go it sounds vaguely like a diesel. Not nearly as noisy but still not the same sound im used to hearing from an EA81. My question is...is this normal for a solid lifter EA81? Ive never owned one so i have no idea. All i will say is this things got a bit more balls than the old motor.

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timing is set to 10 degrees (weber). Valve clearance is .010 for intake valves and .014 for exhaust valves as spec'd by HTKYSA. I was thinking valves as well except for the fact that its damn quiet at idle. And this bottom end has 52k miles on it so i doubt its a rod knock.

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Ive heard detonation before and i dont think this is it. I could be wrong but its not a pinging its more of a diesely sound. I will however back the timing off back to 8 for now and pop some octane booster in there. I think when blew the other motor i had a tank of 89 so thats probably not helping matters. I cant imagine what it would sound like if i had the SPFI pistons as well.

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The noise you are hearing is from you valve adjustment being off due to your head cut the stock valve adjustment of .010 intake and .014 exhaust will no longer work due to the change in your valve geometry from the head shave there is no easy fix due to the lack of after market adjustable push rods to complicate for the shorter distance from the cam to the rocker arms. on the hydro lifter engines the lifters them selves make the difference without much adjustment or having to change the cam out where as in the soild lifter engines they become noisy above and idle without changing the cam shaft out the only way I have found to quite the has been to play with the valve adjustments making them quite a bit titer than the stock settings this has work for me in the past and should work for you but there is alot of guess and check required I finally got my wagon to quite down but it took a while alot of putting on and pulling of the valve covers and when you find the right adjustment write it down some where under the hood or in your repair manual the adjustment I came up with for my wagon is .007 intake and .010 exhuast I have it wrote under the hood you can try this adjustment but reminder every engine/built is different it may work for you and it may not or you could just use it as a starting point

 

 

PS you should not have too use high test gas with this engine if it is timed right the compression should not be more than 9.5 to 1 or 185-190 psi to get any more than that with a ea81 you have to change the pistons ea71 pistons in my engines have around 205-215psi the spfi pistons that are in my brats ea81 got me 220-225psi but that was from my exp.

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I would have only thought i would need to do that if i did a cam as well. I realize that the heads are closer together now but i thought the valve adjustment would have taken care of that. I know of people having issues with the delta cams being noisy because of the different lift. Oh well guess the covers are coming back off.

 

Is it ok to drive with it noisy like that? Am i hurting anything? I just dont know when ill get a chance to adjust it (hopefully this weekend).

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I have had a heck of a time getting mine to quiet down too (EA81) with the Delta grind. Perfect explanation and solutions by 84GL. This is what I have been going through. I spoke with someone at Delta that said sometimes you have to get pretty close to Zero Lash cold on these before they are quiet. I am at .004 and .006 and they are still a little noisy but I am learning to live with it for the extra power it makes.

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I have had a heck of a time getting mine to quiet down too (EA81) with the Delta grind. Perfect explanation and solutions by 84GL. This is what I have been going through. I spoke with someone at Delta that said sometimes you have to get pretty close to Zero Lash cold on these before they are quiet. I am at .004 and .006 and they are still a little noisy but I am learning to live with it for the extra power it makes.

 

But thats the thing that has me puzzled...i have a stock cam....not a delta. I would like a delta eventually when i have more time but for now i just have the shaved heads, weber, and high flow exhaust. I would think i would have problems adjusting valves with the delta but not with a stock cam.

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its the shaved heads which are a necessarily evil when looking for compression on an ea81 its the easiest way and the cheapest to gain a few ponies but its also problematic too being that you have to stand the noise on the soild lifter engines and yes a new cam grind will fix the problem if the cam has .030 less lobe OD but with the head shaved and the valve clearance adjusted right you gain .030 in lift and few degrees in duration with the stock cam and NO A LITTLE VALVE NOISE WANT HURT IT but the stock gap mite hurt it if you run it a few 1000 miles sounding like an old diesel injector pump and it want make the power it could like that either

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Got out and readjusted the valves this morning before work (not often you hear that phrase lol). Anyways i put the intake valves to .007 and the exhaust to .010. Most of the noise is gone now but there is still a bit. I think im going to tighten em down a tad more to around .006 and .009 or so and see what it sounds like then. Thanks for the help though guys!

 

All i will say is damn this thing scoots now. I had it up on the highway and had to pass someone and didnt even bother downshifting to 4th. I just left it in 5th and flew right by them at 80. I would not even imagine being able to speed up that easy before. I cant imagine what it will be like once i install the wideband and tune the carb closer to where the engine wants it.

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I guess I'm not seeing why with a solid lifter engine you can't just adjust the pushrod buckets to take up the .030"?

 

I've taken .020" off of EA81 heads and not had any issues - though that was with a hydro engine.

 

So is there not enough adjustment on them or something? .030" is not that much in the scheme of things....

 

I get that it changes the rocker and push-rod geometry by a bit but is it really that much that you have to change the valve lash? I guess I'm more wondering what causes them to make noise after the change - valve lash is there to compensate for expansion due to operating temp and I guess that would mostly be the pushrod getting slightly longer..... which would cause the rocker to close it's gap with the valve stem. Hhhhmmm - I can see how it could affect it but I hadn't thought that a change of only .030" would result in that much of a difference. The way the geometry works out you would want to close the gap as has been said but without doing a lot of measureing and calculating I can't say for sure how much. Don't adjust them to zero though - that's a good way to break something quick.

 

I must say that most of the solid lifter engines tick slightly even at stock lash settings and so I would be tempted to close them up a bit tighter anyway to get them to shut up.

 

GD

Edited by GeneralDisorder
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I guess I'm not seeing why with a solid lifter engine you can't just adjust the pushrod buckets to take up the .030"?

 

I've taken .020" off of EA81 heads and not had any issues - though that was with a hydro engine.

 

So is there not enough adjustment on them or something? .030" is not that much in the scheme of things....

 

GD

 

there is enough adjustment but the stock specs don't work and the soild lifters don't expand or contract like the hydros do they just make lots of noise chattering taking up slack in the valve train the hydro lifter make up the slack by expanding or contracting there for less adjustment is needed

 

now hatchsub you should have gain at least 10-12 hp by decking the heads even if you have not play with your timing yet I found that ea81s have a sweet spot now that the heads have been shaved thats a little different now than it was before find it and it will probably run and little stonger

 

 

that being said you should have about 83-85 hp now but you will find out theres a bump in hp gains from here on you will have to open the motor up and replace the cam and pistons change the heads to the bigger valve ones and port the crap out of them same goes for the intake and if you run spfi the thottle body becomes a source of restriction

 

and then your at the same point as me hitting the 115-120 hp wall that mosty because of the heads

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that being said you should have about 83-85 hp now but you will find out theres a bump in hp gains from here on you will have to open the motor up and replace the cam and pistons change the heads to the bigger valve ones and port the crap out of them same goes for the intake and if you run spfi the thottle body becomes a source of restriction

 

and then your at the same point as me hitting the 115-120 hp wall that mosty because of the heads

 

 

Heads are the big valve heads. I plan on building a spfi piston/delta cam ea81 with these heads at a later time. Right now its just the heads, the weber and the high flow custom exhaust. Im throwing a wideband on it for a bit and am going to tune the weber using that and see where im at. Im sure i picked up a decent amount of power along with the fact that i already rejetted the weber a bit but need to find out what (if anything) still needs changing. I also upped the timing back to around 10 (going to put a light on it and really fine tune it a bit more). Should be fun.

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I guess I'm not seeing why with a solid lifter engine you can't just adjust the pushrod buckets to take up the .030"?

 

 

GD

 

Im still not sure i completely understand it either but i did get rid of most of the noise by tightening up that clearance. I might just leave it as is because it is livable and going tighter might just hurt performance rather than help.

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It will help right up to the point that it gets too tight and causes a valve or seat to burn. Mine are pretty darn tight (about .004 and .006) and I can still hear them so I'm sure they are ok (this EA81 has ALL the mods with SPFI). The old tired stock solid lifter EA81 I pulled out was really quiet at .010 and .014, go figure. I have been over my valve adjustment several times carefully.

 

@GD you can adjust the valve train to take up the extra .020 or .030 thou but for some reason it doesn't stop the noise.

 

Thanks for the updates and progress reports!

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Sounds like a quieter diesel now lol. I only hear it from idle to about 2k in first gear after that it sounds normal. It def quieted down when i tightened it down. I havent decided if i want to try tightening it down more. I might just leave it as is at your settings.

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Oh for future reference on the cam on my engines the delta 240 tq grind worked best for me I have 2 built ea81s one soild and one hydro the soild one has the delta 260 hp grind I think it been a few years so, anyway the hydro one in my brat runs smoother and has alot more get up and go its the only one I have dyno so I don't on the hp or tq difference but itas the stronger one from the set of the pants dyno pulls harder on hills and every thing other than the cams the engines are about the same built both have big valve heads my verson of spfi pistons head chambers welded up and everything else heads ported bigger valves etc.

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